The data obtained with intravenous and intranasal cocaine have been consistent across a substantial number of subjects and over a variety of different experimental paradigms. They indicate that cocaine, like amphetamine, causes a dose-related increase in heart rate and blood pressure, as well as dose-related changes, similar to amphetamine, in verbal reports of drug effect and mood change. Unlike amphetamine, its effect is short-lived, with a half-life averaging around 40 minutes. The physiological and subjective effects of this drug have a high correlation with the ascending limb of the plasma level curve, but return to pre-drug levels faster than does blood level. There appears to be a tachyphalaxis effect when a dose of intravenous cocaine is administered on top of an inhaled dose while blood levels are still high. Behaviorally, cocaine appears to interfere with repeated task acquisition, but, like amphetamine, it seems to bring performance that has deteriorated due to fatigue back to pre-drug levels. Future research will concentrate on patterns of self-administration of cocaine and the effects of self-administered doses on behavior.